Truss connector plate

ABSTRACT

A truss plate is provided comprising a metal sheet having at least one pair of prongs integrally projecting from the undersurface thereof and forming a single elongated slot in said sheet having a central portion wider than the adjacent portions thereof, the prongs of said pair being disposed at the opposite ends of said slot, each prong comprising an elongated narrow shank and a barbed tip, said barbed tip being wider than said shank at its juncture thereto.

United States Patent inventor Gordon G. Wood 1664 Cliflord 81., GlendaleHeights, 111. 60137 Appl. No. 861,825 Filed Sept. 29, 1969 PatentedSept. 7, 1971 TRUSS CONNECTOR PLATE 10 Claims, 6 Drawing Figs.

US. Cl 85/13, 52/712, 287/2092 L Int. Cl ..E04c 3/292, F16b 5/00 Fieldof Search 287/2092 [56] References Cited UNlTED STATES PATENTS 3,347,12610/1967 Templin et al. 85/13 3,362,277 l/1968 Moehlenpah et al. 85/133,364,805 1/1968 Sanford 85/13 3,416,283 12/1968 Sanford 85/13 X3,417,652 12/1968 Menge ..287/20.92 LP X 3,479,920 1 1/ 1969 Sanford85/13 Primary Examiner-David J. Williamowsky Assistant Examiner-Wayne L.Shedd Attorney-Donald M. Sell ABSTRACT: A truss plate is providedcomprising a metal sheet having at least one pair of prongs integrallyprojecting from the undersurface thereof and forming a single elongatedslot in said sheet having a central portion wider than the adjacentportions thereof, the prongs of said pair being disposed at the oppositeends of said slot, each prong comprising an elongated narrow shank and abarbed tip, said barbed tip being wider than said shank at its juncturethereto.

PATENTEDSEP 71911 3,603 197 sum '2 OF 2 INVILN'IUR.

BY 60RO0N 6W000 4770/?NEY TRUSS CONNECTOR PLATE This invention relatesto connector plates to join abutting wooden truss members to one anotherin the formation of wooden trusses. More particularly, this inventionrelates to a new and useful truss-connector plate having a combinationof plate openings and integral prongs or teeth which provides a uniquecombination of desirable features, and to trusses constructed with suchplates.

The formation of wooden trusses having the abutting members thereofjoined with metal truss-connector plates is quite well known to the art.Wooden trusses having such plate-connected joints are strong andlightweight and support greater loads than similar trusses having thejoints connected by other means, e.g. nails and the like. Thus, usingtruss-connector plates, in lieu of or in conjunction with nails, woodentrusses having longer spans and lower pitches than were theretoforepossible can be constructed. Also, truss fabrication is simplified andthe speed of production greatly increased.

Nonetheless, the prior known truss-connector plates have certaindeficiencies. High strength in the truss joint fonned using a connectorplate is usually gained only by increasing the thickness of theconnector plate as none of the commercially used plates can be appliedone on top of the other; good holding strength of the plate to the trussmembers is usually achieved only by providing a large number of teethper square inch, usually eight or more; many plates require the use ofstitching nails in addition to the teeth of the plates; when trusses arestacked together, both stacking and separation are sometimes difiicultas the plates of adjacent trusses tend to catch against one another.

The truss-connector plate of the present invention provides a uniquecombination of properties, combining high strength and tenacious holdingpower with lightweight and a minimal number of prongs. The plates ofthis invention, although having elongated slotlike openings from whichthe prongs are punched, are nevertheless provided with barbed prongswhich are arranged in rows and in such a way that the plates can bereadily overlaid one upon the other, the barbed prongs of the overlyingplate extending through the openings of the underlying plate, to provideincreased strength at areas of high stress in wooden trusses, therebyeliminating the need of special underlay plates or plates of heaviergauges as have been heretofore required in such areas.

In general, the truss-connector plate of this invention comprises arectangular plate of sheet metal or the like having at least one pair ofprongs integrally projecting from the undersurface thereof and forming asingle elongated generally rectangular slot in said sheet, the prongs ofeach pair being disposed at opposite ends of the slot with each prongcomprising an elongated narrow shank having a barbed tip, the barbed tipbeing wider than the shank at its juncture thereto.

A preferred form of connector plate in accordance with the invention isa flat rectangular plate having embossed side edges which dig into thewood of the truss to make the edges of the plate flush with the trusswood. Each plate or plate section is provided with four rows of slots,each slot being in the form of a pair of lineally offset partiallyoverlapping elongated rectangles so that the slot comprises lineallyoffset narrow end portions and an enlarged central portion. The slots ineach row are equidistant from another and each row of slots is staggeredand these slots thereof are reversed relative to the slots of eachadjacent row. Also, the distance between the slots of each row islightly less than the length of each slot and each prong is twisted sothat the barbed tip thereof fits through the narrow end portion of theslot of an underlying plate of identical construction. Each four rows ofslots are separated by the indented embossment. Thus, each plate hasfour rows of slots equidistant from one another. Larger plates aremultiples of the four-row slotted arrangement wherein the distancebetween each four-row grouping of slots is greater than the distancebetween rows of each grouping. This arrangement provides thestaggeredrow slot construction with even higher tear resistance. Also,with this construction, when the plates are overlaid one upon the otherwith each row of slots of the overlying plate spanning the distancebetween the slots of each staggered row of reversed slots of theunderlying plateoverlaid thereby, the prongs of the overlying plate gothrough the slots of the underlying plate; this versatility is unique ina truss-connector plate.

This new plate, and other and further features thereof, are described inmore detail in conjunction with the accompanying drawings wherein apreferred form of this plate is illustrated and wherein:

FIG. I is a top plan view of a connector plate made in accordance withthis invention;

FIG. 2 is a side view of the plate;

FIG. 3 is a bottom view of the plate;

FIG. 4 is an enlarged perspective of a portion of the underside of theplate;

FIG. 5 is an end view of the plate; and

FIG. 6 is a bottom plan view of a pair of plates, one overlying theother.

Referring to the accompanying drawings in more detail, there isillustrated in FIGS. 1-4 a preferred form of connector plate designatedin its entirety by the numeral 10. The plate illustrated is an elongatedflat rectangular plate of sheet metal or the like having a planar topsurface with indented side edges 12 (which appear as embossed whenviewing the undersurface of the plate) and four longitudinally extendingrows, l4, l6, l8 and 20, respectively, of elongated generallyrectangular-shaped slots 22 therein. From the undersurface of the plate10 integrally project prongs 24, there being one pair of prongs 24 foreach slot 22, the prongs of each pair being disposed at the oppositeends of the slot from which they have been forced by a punch press orthe like.

Each of the slots 22 is in the shape of a pair of partially overlappingelongated rectangles lineally offset from one another forming a widecentral portion 26 and narrower lineally offset end portions 28 and 30.

Turning particularly to FIG. 4, the construction of the prongs 24 ismost clearly observed. Each prong 24 is generally V-shaped in crosssection for strength and comprises an elongated shank 32 havinggenerally parallel edges and a barbed tip 34 equipped with barb 36, thebarbed base of the tip 34 being wider than the shank 32 of the prong.

By observing the bottom of the plate 10 as illustrated in FIG. 5 it willbe seen that the prongs 24 are twisted from the base of the tip,although remaining perpendicular to the plane of the plate, so that thebarbed tip 34 of each prong 24 is no wider at its widest point than thewidth of the narrow end portions 28, 30 of each of the slots 24.

The distance between slots in each row is less than the overall lengthof each of the slots. In each four-row plate, or section of plate in theevent the four-row sections are not separated from one another along theembossed areas (FIG. 6), rows 14 and 18 are identical and rows [6 and 20are identical, rows 16 and 20 being staggered relative to rows 14 and 18and having their slot pattern reversed from that of rows 14 and 18. Byconstruction of the plates in this manner as described, the plates 10 ofthis invention may be readily overlaid one upon the other to increasethe strength of a joint wherever such strength increase is necessary. Todo this, as illustrated in FIG. 6, it is only required that theoverlying plate be reversed with respect to the underlying plate. Inother words, the overlying plate in FIG. 6 is shown with its slot rowsl420 reversed with respect to the corresponding rows of the underlyingplate 10.

The plate thus constructed is a remarkably good connector plate. Theslot shape and arrangement of the rows of slots provide a universalplate construction whereby the plates can be overlaid congruently orotherwise, one upon the other to provide the plate with a uniqueversatility. The lineally offset barbed prongs of each row of prongsprojecting from the underside of the plate provide tremendous holdingpower in .wood without undue disruption of the wood fiber while theshape and arrangement of the resultant slots provide a plate which,while of thin gauge metal, is very resistant to tearing.

In tests conducted by the Pittsburgh Testing Laboratory on tensionassemblies having the joints secured by truss-connector plates of thekind illustrated in the drawings, a design value of 220 pounds persquare inch was approved by the Federal Housing Administration fortrusses made of any of southern yellow pine, west coast Douglas fir orwest coast hemlock. So far as I am aware this is the only connectorplate having this high a design value assigned for all three woodspecies.

These plates as presently constructed average seven teeth or prongs persquare inch. The slots of each plate are each 1&- inch long andlongitudinally spaced on Vii-inch centers and in staggered rows 5/ l6-inch apart in each four-row grouping and %-inch apart where thefour-row groupings are interrupted with an ernbossment 12. With thisarrangement, the plates possess great tear strength, forcing a diagonaltear pattern under tearing stress. Further in the multisectioned plate,

where the distance between rows flanking the embossed area (or areaswhere the plate is made up of more than two fourrow sections) is greaterthan the distance between the rows in each section, the resistance totear is further increased. Adjacent prongs in each row alternate as tothe direction of twist and barbed edge.

While the plates of this invention are generally described astruss-connector plates, this term is in no way meant to limit theenvironment of their use. Thus the plate lends itself to.

such connection, or it may be used as a retainer plate or cleat to fixcrates and the like in place relative to one another or to the confiningareas of railroad cars, trucks, ships, etc. It may also be used to joinwall sections to one another, or as a general fastening plate whereverrequired.

That which is claimed is:

l. A connector plate comprising a metal sheet having at least one pairof prongs integrally projecting from the undersurface thereof andforming a single elongated slot in said sheet having generally parallelend portions lineally offset from one another and an enlarged centralportion, the prongs of said pair being lineally offset from one anotherand being disposed at the opposite ends of said slot, each prongcomprising an elongated narrow shank and a barbed tip, said barbed tipbeing wider than said shank at its juncture thereto.

2. A connector plate in accordance with claim 1 wherein said plate has aplurality of parallel, equidistantly spaced rows of said slots therein,adjacent rows of said slots being staggered relative to one another andthe distance between slots in each row being less than the length ofeach slot.

3. A plate in accordance with claim 2 wherein said prongs are twisted sothat the apparent width thereof is less than the width of said slotadjacent the endsof the slotwherebysaid plate is capable of being laidover another identical plate with the prongs of the overlying plateprojecting through the slots of the underlying plate.

4. A connector plate comprising a metal sheet having parallel rows ofelongated slots therethrough, each slot having been formed by a pair ofprongs integrally projecting from the un dersurface of said sheet, theprongs of each pair being disposed at the opposite ends of theirassociated slot in lineally offset relation to one another, each prongcomprising an elongated shank having a barbed pointed tip, the barbedbase of said tip being wider than said shank, each of said slots beingin the shape of a pair of partially overlapping elongated rectangleslineally offset from one another forming a wide central portion andnarrower lineally offset end portions, the slots of adjacent rows beingstaggered relative to one another.

5. A connector plate in accordance with claim 4 wherein said prongs aretwisted so that the apparent maximum width thereof approximates thewidth of the end portions of said ing a flat metal sheet havin aplurality of equidistantly spaced rows of generally rectangu aridentical slots therein, the slots of each row being equidistant fromone another, each slot being in the shape of a pair of lineally offset,partially overlapping rectangles and having narrow lineally offset endportions and an enlarged central portion, said plate having prongsintegrally projecting from the undersurface thereof, said prongsdepending from the end of each slot, there being one pair of prongspunched from the material forming each slot, each prong having astraight shank terminating in a barbed tip, the barbed portion of thetip being wider than said shank.

7. The connector plate of claim 6 wherein adjacent rows of slots arestaggered relative to one another and the slots of adjacent rows arereversed relative to one another, the distance between the ,slots ofeach row being slightly less than the length of each slot, each prongbeing twisted so that the barbed tip thereof tits through the slot of anunderlying plate of the same construction whereby the plate can beapplied over a plate having an identical slot and prong arrangement byoverlaying the plates so that each slot of each row of slots of the topplate spans the distances between adjacent slots of each reversed row ofslots of the underlying plate.

8. The connector plate of claim 7 wherein said plate is rectangular, theside edges of each plate being embossed to stifien the plate and causethe plate edges to press into .the wood upon application to a truss.

9. The connector plate of claim 8 wherein the side edges of each plateare embossed to stifien the plate and cause the plate edges to pressinto the wood upon application to connect the joint of atruss.

10. The connector plate of claim 6 wherein the shortest distance betweenthe slots of adjacent rows is shorter than the distance between theslots of each row whereby the plate will tear diagonally under stress.

1. A connector plate comprising a metal sheet having at least one pairof prongs integrally projecting from the undersurface thereof andforming a single elongated slot in said sheet having generally parallelend portions lineally offset from one another and an enlarged centralportion, the prongs of said pair being lineally offset from one anotherand being disposed at the opposite ends of said slot, each prongcomprising an elongated narrow shank and a barbed tip, said barbed tipbeing wider than said shank at its juncture thereto.
 2. A connectorplate in accordaNce with claim 1 wherein said plate has a plurality ofparallel, equidistantly spaced rows of said slots therein, adjacent rowsof said slots being staggered relative to one another and the distancebetween slots in each row being less than the length of each slot.
 3. Aplate in accordance with claim 2 wherein said prongs are twisted so thatthe apparent width thereof is less than the width of said slot adjacentthe ends of the slot whereby said plate is capable of being laid overanother identical plate with the prongs of the overlying plateprojecting through the slots of the underlying plate.
 4. A connectorplate comprising a metal sheet having parallel rows of elongated slotstherethrough, each slot having been formed by a pair of prongsintegrally projecting from the undersurface of said sheet, the prongs ofeach pair being disposed at the opposite ends of their associated slotin lineally offset relation to one another, each prong comprising anelongated shank having a barbed pointed tip, the barbed base of said tipbeing wider than said shank, each of said slots being in the shape of apair of partially overlapping elongated rectangles lineally offset fromone another forming a wide central portion and narrower lineally offsetend portions, the slots of adjacent rows being staggered relative to oneanother.
 5. A connector plate in accordance with claim 4 wherein saidprongs are twisted so that the apparent maximum width thereofapproximates the width of the end portions of said slots.
 6. A connectorplate adapted to connect abutting components of a wooden truss to oneanother, said plate comprising a flat metal sheet having a plurality ofequidistantly spaced rows of generally rectangular identical slotstherein, the slots of each row being equidistant from one another, eachslot being in the shape of a pair of lineally offset, partiallyoverlapping rectangles and having narrow lineally offset end portionsand an enlarged central portion, said plate having prongs integrallyprojecting from the undersurface thereof, said prongs depending from theend of each slot, there being one pair of prongs punched from thematerial forming each slot, each prong having a straight shankterminating in a barbed tip, the barbed portion of the tip being widerthan said shank.
 7. The connector plate of claim 6 wherein adjacent rowsof slots are staggered relative to one another and the slots of adjacentrows are reversed relative to one another, the distance between theslots of each row being slightly less than the length of each slot, eachprong being twisted so that the barbed tip thereof fits through the slotof an underlying plate of the same construction whereby the plate can beapplied over a plate having an identical slot and prong arrangement byoverlaying the plates so that each slot of each row of slots of the topplate spans the distances between adjacent slots of each reversed row ofslots of the underlying plate.
 8. The connector plate of claim 7 whereinsaid plate is rectangular, the side edges of each plate being embossedto stiffen the plate and cause the plate edges to press into the woodupon application to a truss.
 9. The connector plate of claim 8 whereinthe side edges of each plate are embossed to stiffen the plate and causethe plate edges to press into the wood upon application to connect thejoint of a truss.
 10. The connector plate of claim 6 wherein theshortest distance between the slots of adjacent rows is shorter than thedistance between the slots of each row whereby the plate will teardiagonally under stress.